T = int(input())
if T >= 30:
  print("Yes")
else:
  print("No") T = int(input()) T int(input()) int input() input if T >= 30:
  print("Yes")
else:
  print("No") T >= 30 T 30 print("Yes") print "Yes" print("No") print "No" T = int(input()) int(input()) T
T = int(input())
if T >= 30:
  print("Yes")
else:
  print("No")